Aminomethyl-substituted organopolysiloxane as water-repellent and gloss-imparting coating for lacquered metal surfaces

ABSTRACT

EXCELLENT HYDROPHOBIC PROPERTIES AND PLEASANT GLOSS ARE IMPARTED TO SOLID, ESPECIALLY SMOTH, SURFACES, FOR EXAMPLE LACQUER COATINGS OF THE BODIES OF MOTOR VEHICLES, BY APPLYING THERETO, ACCORDING TO THE INVENTION, NEW COATING COMPOSITIONS CONTAINING AS THE EFFECTIVE AGENT AN ORGANOPOLYSILOXANE WHICH IS AMINOMETHYL-SUBSTITUTED ON AT LEAST TWO OF ITS SILOXANE UNITS, CORRESPONDING TO THE FORMULA   CH3-(SI(-CH3)(-CH2-N(-R)-R&#39;&#39;)-O)N-(SI(-CH3)2-O)(P-N)-   SI(-CH3)(3-A)-(CH2-N(-R)-R&#39;&#39;)A   OR TO THE FORMULA   CH3-(SI(-CH3)(-CH2-NH(+)(-R)-R&#39;&#39;)-O)N-(SI(-CH3)2-O)(P-N)-   SI(-CH3)(3-A)-(CH2-NH(+)(-R)-R&#39;&#39;)A (X(-))(N+A)   IN WHICH P IS AN INTEGER GREATER THAN 25, A IS 0 OR 1, N IS AN INTEGER GREATER THAN (1-A) AND SMALLER THAN P/10, R AND R&#39;&#39;, INDEPENDENTLY OF ONE ANOTHER, ARE HYDROGEN ATOMS OR ALKYL OR CYCLOALKYL RADICLS HAVING LESS THAN 9 CARBON ATOMS, AND X IS A MONOVALENT ACID RADICAL.

United States Patent ice 1 371132 3737336 h" 't' s fild AMINOMETHYLSUBZSTITUTED ORGANOPOLY- T 18 1s a dlVlSlOl'l, of applica 101'1 Ser No 17,9 8 e SILOXANE AS WATER-REPELLENT AND 1970 now abandoned.

FOR The present invention relates to novel coating com- Hans Dietrich Golitz, deceased, late of Cologne-Stammpositions which impart lasting hydrophobic properties heim, Germany, by Ingrid Golitz, heir, and Walter Noll, Opladen, Karl Schnurrbusch, Leverkuse st i and, in addition, a pleasant gloss to solid, especially buchel Klaus Seyfried Cologne and Walter Simmler th f f Odentlial-Globusch, Germany, sissignors to Farbeufa Smoo Sur aces for eyfamp Is to the lacquer coa mgs o briken Bayer Aktiengesellschaft, Leverkusen, Germany the l s f m t r v hl l s.

10 No Drawing. Original appllcahon Mar. 9 1970, Ser. No.

17958 Divided and this application Dec. 22, 1971, It lS known to use for this purpose poydlmethylsiloxane Ser. No. 210,944 oils in combination with waxes. Such agents for the care Int. Cl. B32]: /08; B44d 1/36 Us. CL 7 Claims of lacquer are not satisfactory, however, because they 15 cannot be applied with sufiicient ease, give only poor ABSTRACT OF THE DISCLOSURE hydrophobic properties and a weak gloss, and are easily Excellent hydrophobic properties and pleasant gloss are removed from the Substrate by means of detergents.

imparted to solid, especially smooth, surfaces, for example lacquer coatings of the bodies of motor vehicles, by pp y g thereto, according to the invention, 116W Coating Waxes, short-chain polydimethyl-siloxanes with terminal compositions containing as the effective agent an organopolysiloxane which is aminomethyl-substituted on at least two of its siloxane units, corresponding to the formula same disadvantages with regard to evenness of distribu- The more recently disclosed composition, consisting of silanol groups and aminoalkylalkoxy-silanes, have the or to the formula 69 R-NH-R 0H, OH; R g. |EB CH3 1o- -si-0- s1(oH3)3.. -CH -IIIH X m,

L (3H3 n 6H8 u-n J R, n

in which tion on the surface of the substrate and also the gloss p is an integer greater than 25, obtained a is 0 or 1, Coating agents which are more advantageous, espel l g g greater than 0-) and Smaller than cially for the care of lacquer and polish, have now been p V R and independently of one another are hydrogen found in the form of certain linear or gano srloxane co atoms or alkyl or cycloalkyl radicals having less than polymers which are aminomethyl-substrtuted on at least 9 carbon atoms, and tWo of their siloxane units. These polymers correspond X is a monovalent acid radical. to the general formula $113 lHa J R or to the general formula in which p is a number greater than 25, preferably one of the numbers from 45 to 250;

a is or 1;

n is a number greater than (la) and smaller than p/ 10,

preferably a number between 12/ 40 and p/ 15;

R and R, independently of one another, are hydrogen atoms or alkyl or cycloalkyl radicals with less than 9 carbon atoms; and

X is a monovalent acid radical, preferably a fatty acid radical having 1 to 3 carbon atoms.

Compounds of this type can be obtained by several known methods, for example by the hydrolysis of mixtures of the calculated amounts of methyl-substituted and methyland bromomethyl-substituted chlorosilanes, and the reaction of the resultant siloxanes of the general in which Z is Cl or (preferably) Br, with an excess of an amine of the general formula RNHR'. The aminebasic polysiloxanes initially obtained can then be converted with acids, e.g. acetic acid, into the corresponding salts.

The aminomethyl-substituted organo-siloxane copolymers of the formulae given above have the unexpected property of spreading extremely quickly over the surfaces of a wide variety of substances to form coherent films and to impart to these surfaces hydrophobic properties withstanding the attack of detergents, even if these are many times applied, which properties cannot be achieved by conventional means. The aforesaid copolymers are therefore eminently suitable for the preparation of agents for the care of lacquer which, in contrast to the compositions mentioned in the second and third paragraphs hereof, can be applied extremely easily. For example, it is only necessary to pour their solutions in water-miscible solvents, such as isopropanol or acetone, which solutions may also contain a small excess of an acid of the general formula XH, into a great excess (e.g. twenty times their weight) of water or to introduce them into a water current by means of an injector, to prepare, in the simplest possible way, an emulsion which can easily be applied to the surface to be coated by spraying, pouring, spreading or dipping. There remains only to remove the excess emulsion by rinsing with water; the residual rinsing water then lies on the treated surface, for example the external surfaces of a motor vehicle, in the form of droplets of so wide an angle of contact that they are blown away simply by the current of air caused by driving. Repolishing, which is necessary when conventional coating agents are used, can be dispensed with in this case, as the surfaces immediately acquire a gloss of such quality that it can not be improved even by polishing.

The protective film attained by means of the surface treatment according to the invention proves to be very resistant to detergents; the gloss and the water-repellent effect are not reduced even by washing ten times with one of the conventional detergent solutions.

The following examples are given for the purpose of illustrating the invention.

EXAMPLES 1 TO 4 A series of four organo-polysiloxane copolymers according to the invention are obtained by first hydrolyzing in known manner mixtures of organo-chlorosilanes of the fo mu ae nd in h amo nt g e b ow he p s are parts by weight), and equilibrating the hydrolysis products in the presence of acid-activated bleaching earth. The mixture components used for the purpose are 8900 parts (CH SiCl each time and, in addition, in

Example 1, 416 parts BrCH Si(CH )Cland 435 parts Example 2, 416 parts BrCH Si(CI-I )Cl and 375 parts BrCH Si (CH C1;

Example 3, 580 parts BrCH Si(CH )Cl and 525 parts Example 4, 375 parts BrCH Si(CH Cl.

The brominated methyl-polysiloxane oils resultant from the equilibration are reacted in Examples 1, 2 and 4 with 2400 parts, and in Example 3 with 4000 parts, of cyclohexylamine, the oil is separated from the precipitated cyclohexyl-ammonium bromide by filtration, and the liltrate is separated from the excess of cyclohexylamine by evaporation under reduced pressure. There remain polysiloxanes of Formula I in which R is cyclohexyl, R' is H and in Example 1: a=0, n=2 and p=30; Example 2: 01:1, 11:3 and 12:72; Example 3: w=1, n=3 and 2:48; Example 4: a1=1, n=1 and 12:69.

Portions of parts thereof are mixed in Example 1 with 8 parts acetic acid; Example 2 with 8 parts acetic acid; Example 3 with 11.2 parts acetic acid; Example 4 with 4 parts acetic acid,

and, in addition, in one series of Examples, 1a to 4a, with 292 parts isopropanol, and in a second series of Examples, 1b to 4b, with 292 parts acetone. In this way there are obtained eight solutions of salts of Formula II, in which X is CH C(O)O.

The properties of the coatings which can be produced with these eight solutions were tested as follows:

Eight pieces of sheet iron which were coated with car body lacquer were washed with an aqueous solution of 0.1 percent by weight of an anion-active detergent which is at present commercially available under the trade name Pril. An emulsion was prepared from each of the solutions 1a to 4a and 1b to 4b described above by pouring 25 cc. of each solution into 10 litres of water. Each of the emulsions was poured over one of the washed pieces of sheet iron, and then rinsed off with water. The lacquered surfaces of all the sheets were then so waterrepellent that the drops initially remaining thereon could easily be blown off, and the surfaces exhibited excellent gloss.

The resistance of the coatings produced according to the invention to washing was tested by impregnating a soft sponge with the detergent solution used before, rubbing the coated surfaces for one minute and then rinsing with water. This wash cycle was repeated nine times with the result that only the lacquer surfaces treated with the emulsions of Examples 3a, 3b and 1b exhibited a marked reduction of gloss and hydrophobicity.

A metal sheet treated for comparison with a commercial washing preservative and treated analogously showed a marked reduction of hydrophobicity even after the first wash cycle, and a complete loss of hydrophobicity after the second wash cycle.

What we claim is:

1. The method of imparting gloss and water-repellency to lacquered metal surfaces, which comprises coating said surfaces with an agent comprising as the essential ingredient a, salt 9f a fl w b e am qme y -s bst tuted li ear 6 organosiloxane copolymer, said salt corresponding to the 5. A method according to claim 3, said agent comgeneral formula prising a small excess of an acid of the formula XH.

69 RNHR i CH3 R I, 1e 9) CH3 -s 1-o s 1-0 s1(cH3)3 CHg-IIIH X M.

L CH3 H CH3 p-nJ R u in which 6. A method according to claim 3, wherein the agent and solvent are mixed with at least 20 times their weight p is an integer greater than 25 up to about 250; in water selecied from Zero and one; 7. A method according to claim 1 wherein in said n is anlanteger greater than (1-a) and smaller than copolymer X is the radica1CH3C(O)O.

I i R and R, independently of one another, are selected References Cited from the group consisting of hydrogen atoms and UNITED STATES PATENTS alkvl and cycloalkyl radicals having less than 9 car- 2 947 771 8/196O Bailby 260 448 2 N oon atoms; and X is a monovalent acid radical. 3:1 8 260-4482 2. A method according to claim 1, wherein in said co- 3087909 4/1963 a gi E polymer 1 3,336,158 8/1967 Wada et a1. 117-132 BS X fig from 45 to 9 3,247,281 4/1966 Gagliardi 117161 ZA X get P t and 3 058 850 10/1962 Sell 117 161 ZA X X is a fatty acid radical having 1 to 3 carbon atoms. 3:222213 12/1965 Clark 1l7 75 X 3. A method according to claim 1, said agent com- 25 prising in addition to said copolymer a water-miscible RALPH HUSACK Primary Examiner solvent.

4. A method according to claim 3, wherein said solvent R- is selected from acetone and isopropanol. 106287 SB; 117--132 BS, 161 ZA; 260-465 E, 448.2 N 

